True absurdist musicals are few and far between, and you'll only need a trip to the York Theatre Company to be reminded of exactly why that is. The York's new production of Ionescopade is something of a train wreck, but only of model trains, which makes it alternately fun and frustrating. In fact, much like the works of its namesake, Eugene Ionesco, it's half deadly serious and half overly buoyantthe biggest flaw in this mounting is that you never feel that either its director-choreographer, Bill Castellino, or its cast are aware it's supposed to be both at the same time.

In many shows that might not be a big deal. But here it is, because Ionesco and musical revues each rely on a perfect balance to come across as ingratiating rather than gratingthough the two styles are not always compatible. At their best, Ionesco's plays conjure upon the stage wackadoo worlds that nonetheless adhere to a certain logic that you accept because you're given no other choice, caught as you are in the stifling, even crushing ridiculousness that defines the pain of modern existence. Musicals tend to make a bit more outward sense and are more openly presentational; their reality is heightened in a different way, such that singing and dancing become the natural outgrowths of familiar feelings in (usually) familiar circumstances.

Moving between the two visions of theatricality is a challenge because Ionesco's twirling-on-the-verge characters do not readily sing, and musicals' characters' recognizable lives are augmented by outside music and not some addiction to the unexpected made corporeal. Ionescopade, a hit during the 1970s, demands a constant oscillation between these attitudes: Mildred Kayden has scribed a clever collection of peppy songs that hint at, but don't wallow in, Ionesco's unique personality, and bridge the various snippets, scenes, and monologues lifted from the playwright's work. (Robert Allan Ackerman originally conceived the show.) But if all the parts and the performers are not precisely aligned, they'll tangle themselves into knots well before you tingle from the effect.

That's what happens here. Nancy Anderson, Paul Binotto, David Edwards, Leo Ash Evens, Susan J. Jacks, and Tina Stafford are superb and rangy musical performers, who have no trouble plowing through the likes of gender-bending cabaret spot ("Everyone Is Like Me," suggested by Jack or The Submission), a fable about dictatorial poultry ("Mother Peep," inspired by The Killer), a broken-down ballad ("Madeleine," woven together from Ionesco's journals), the sultry "Fire" (adapted from The Bald Soprano), and many more. Their voices and footwork are so polished, and their personalities so carefully constructed and managed, that during the songs they easily summon the entertainment equivalent of Ionesco's impossibilitiesand delight, if never quite transport, you.

But, sad to say, Castellino doesn't help the cast deliver the same goods once the music (bouncily conducted by Christopher McGovern) stops. With lengthy scenes either cobbled together from, or simply extracted from, Ionesco's works, there's at least as much to say as there is to sing, and that requires a more coordinated attack than has been plotted here. There's no subtlety, no subtext, just piercing comedy and almost-comedy, which makes it a chore to sell (or sit through) unsettling vignettes from "The Cooking Lesson," the groupthink parable "The Leader," or Berenger's chilling speech from The Killer. And in what should ideally be a comic showpiece, the everyone's-to-blame three-way pile-up "The Peace Conference," the timing is so off, the actors' approaches so robotic, and the staging so muddled that few laughs and no shivers sneak through.

If not for Samuel Cohen, who plays an onstage Ionesco analogue known only as "The Little Man," the non-sung portions would be a near-complete loss. But Cohen's wino-inspired pantomime and magical way of introducing and playing out scenes is exactly in tune with the kind of sparkling unpredictability that this production needs more of. When he kicks up his feet, flails his hands, and throws a broad smile as he ushers you into a borderline-tragic reenactment of something or other, you feel exactly the appreciation, and apprehension, for nonsense Ionesco so embraced throughout his works.

A pleasing unit set by James Morgan and whimsical costumes by Nicole Wee guarantee that the production at least looks as vibrant as Cohen actsand a bit of eye candy always helps sour pudding go down more smoothly. Ionesco knew that; in fact, it was often his raison de theatre. But without a more intimate relationship between the musical and non-musical portions of the evening, this version of Ionescopade is more a trial than a triumph.

IonescopadeThrough February 26
York Theatre Company at The Theatre at Saint Peter's
Citigroup Center, 619 Lexington Avenue at 54th Street
Tickets online and current Performance Schedule: www.yorktheatre.org